Очень жал что такую интересную дискуссию настолько трудно понимаю. Тема и вообше концепцие понял, но ваше решение и мнение не... Извините если я повтораю ваше мнении.

From what I understand, the transition "from ДВБ to БВБ mode" during the lock-on does not affect gyro-stabilization. Rather, it affects the PRF (ЧПИ). Consider the English translation of MiG-29 flight manual describing the use of "AUTO" regime in search mode:

"In this mode, the coverages are similar to those in the ENCOUNTER (В) and PURSUIT (Д) modes. That is - when the target flies on the head-on course, the target detection occurs at the ranges similar to those in the ENCOUNTER mode. From the range less than 30 km, the target blip is observed in each scanning cycle (Hi PRF and Med PRF) due to the measurements also at the medium repetition frequency (at the ranges less than 10 km, ONLY at the medium repetition frequency)."

So - at the ranges less than 10 km, only the Med PRF can detect the target? It means - lock on must use Med PRF at ranges less than 10 km, and this is the reason to "change over to БВБ mode at 10 km range".

It may also answer the question - in what regime will be the radar, if the lock-on is broken? If the lock-on was broken at the range less than 10 km, it is advantageous for the radar to return to БВБ mode, instead of ДВБ mode, so to more quickly re-acquire the near target. If it's desired to resume ДВБ search mode, the pilot should press the "reset" switch.

To say that the antenna will suddenly change the coordinate system - that is, to rotate mechanically from gyro-stabilized to non-gyro-stabilized position at 10 km distance - it's almost impossible to believe. The angular velocity of the target is faster at short range, so it's a sure way to completely lose the lock. Much more probable is that during the 2-7 seconds required to accomplish the initial ДВБ lock on, that is the time when the antenna is changing from gyro-stabilized to non-gyro-stabilized, IMHO.

The F-15 documentation is somewhat difficult to understand because it does not use the phrase "gyrostabilization in roll", but rather, "space-stabilized" - without any distinction if roll is included or not. What is written, however, is that the search modes are "space-stabilized". It is also written in the Czech document about MiG-29 radar that I presented in an earlier message - "Gyrostabilizace anteny v 'prehledu'" = Gyrostabilization of antenna in the review (search mode).

The western radar will change to Hi or Med PRF as necessary, regardless if Hi or Med PRF is selected on the radar control panel. The radar control panel defines only the "starting" search mode of the radar. HOTAS controls and other functions override this selection when using TWS, auto-acquisition submodes, or guiding missiles. The starting search mode defined by the radar control panel is then ignored, until the pilot presses the "reject" (cancel) button. Then the radar will return to the starting search mode. I think the "reset" switch in MiG-29 has the same function.

My suspicion: aircraft roll does not break the lock, neither for Russian nor for western fighters.

Hope this helps,

-SK